1. Field of the Invention
The present invention relates to an organic EL (electroluminescence) light emitting device utilizing an organic EL element. More particularly, the present invention relates to an organic EL light emitting device having a construction suitable for securing a quantity of light.
2. Description of Related Art
Currently, organic EL light emitters each utilizing an organic EL element have already been brought into practical use as a display device, an illumination device, a back light for a liquid crystal display, etc.
An organic EL light emitter generally has a construction in which a transparent electrode, an organic layer and a cathode are laminated in this order on a surface of a transparent substrate. Accordingly, when a voltage is applied between the transparent electrode and the cathode to flow a current in the organic layer having a hole transport layer, a light emitting layer, an electron transport layer, etc., light is emitted from the light emitting layer. Part of the emitted light is transmitted through the transparent electrode and the transparent substrate in the thickness direction, and is radiated to the outside from the back side of the transparent substrate.